1. Field of the Invention
The present invention relates to an application unit that can be used, in particular, in the fields of pharmacy, cosmetics, dermatology, hair care, etc. The invention concerns more particularly a device of the type comprising a solid or semi-solid applicator which must be brought into contact with a liquid composition before its application, and which is capable of solubilizing or gelling on its surface on contact with the liquid composition. By way of example, this may be a lipstick that is but slightly friable and whose surface must be brought into contact with water, for example, in order to soften its surface and to promote the exfoliation of the lip rouge. Again by way of example, the applicator may be of the xe2x80x9cstyptic pencilxe2x80x9d type for cauterizing sores. In this latter application, the applicator contains hydrosoluble active substances, such as mixed sulphates of aluminium and ammonium, which are solubilized in the presence of a liquid composition such as water. The invention also applies to the application of a product which may have a cosmetic effect and a treatment effect, the cosmetic effect being produced by the applicator itself, the treatment effect being obtained by a liquid solution with which the applicator is brought into contact. By way of example, this concerns a lipstick that is brought into contact with a film-forming agent or with a treatment composition of the anti-chapping type. It may also be a stearate soap of ammonium or potassium, or a tensioning stick, for example of polyvinyl alcohol (PVA) capable of effacing wrinkles, or of guar gum. It may also be a compound, such as an emollient, which cannot be introduced into the stick during its manufacture. In general, the invention relates to any friable solid or semi-solid applicator which, before its application to a surface to be treated, has to be brought into contact with a liquid composition permitting its exfoliation, and/or containing active agents that cannot be introduced into the applicator.
2. Description of the Related Art
EP-A-612 488 describes an applicator comprising a reservoir containing a product to be applied, a cap intended to close the reservoir, and an applicator holder supporting a deformable element made of foam or an elastomer of low hardness for the application of the product. The deformable element carries asperities on its surface and is provided with a good (large) shape memory. The product reservoir is delimited by a capillary end fitting, in the form of a glove finger having a bottom that is provided with a seat pierced by at least one capillary opening, against which the deformable element is applied and deformed in the position when the reservoir is closed by the cap.
In the field of lipsticks there exist, moreover, liquid formulas containing polymers, which have the advantage of a long hold on the lips, but which are, in a galenical form, a long way from the established usage of the conventional stick.
Thus one of the objects of the present invention is to provide an application unit containing both a friable solid or semi-solid applicator and a liquid composition necessary for its exfoliation and/or containing active agents which have to be brought into contact with the applicator with a view to a combined action. Other objects of the invention will become apparent from the description that follows.
In accordance with the invention, these objects are attained by means of an application unit comprising a first compartment intended to form a housing for an applicator containing a product capable of solubilizing or gelling on its surface in contact with a liquid composition, and mounted in a detachable manner in the first compartment through a first opening; a second compartment separated from the first compartment and comprising an element impregnated with the liquid composition and capable of restoring a quantity of the liquid composition to the applicator when the applicator is introduced into the second compartment through a second opening and caused to bear on a restoring surface of the element, the element forming a stopper so as to prevent any flow of the liquid composition through the second opening; and detachable closing means for respectively obturating the first and second openings. The element contained in the second compartment thus acts as a xe2x80x9csequesteringxe2x80x9d agent which retains the liquid to prevent it from flowing by gravity through the second opening, but which restores it to the applicator when the applicator is caused to bear on the element.
The impregnated element may be formed by a block of foam with open cells or half-open cells, or an element forming a wick of the felt type, or a sintered element, or an elastomer of low hardness with open cells or half-open cells, or a combination of such elements. An elastomer of low hardness is understood to mean an elastomer whose hardness is in the range from 15 Shore A to 70 Shore A. Advantageously, the restoring surface of the element is covered by a flocked coating, or by a perforated film of a thermoplastic elastomer, or by a plastic, or by a layer of felt, or by a textile fabric. This last characteristic makes it possible, inter alia, to adjust the quantity of the liquid transferred to the applicator by substantially modifying the restoring capacity of the impregnated element towards the applicator, and/or modifying the abrasiveness of the restoring surface.
The liquid composition may be dosed so as to be contained substantially wholly inside the element. This diminishes the risk of inopportune outflows of the product while ensuring an adequate self-sufficiency for the device.
According to one embodiment, the element has a first end in the vicinity of the second opening, and a second end on the opposite side to the first, the element having, at least at its first end, a cross-section substantially identical with the internal cross-section of the second compartment. This makes it possible to isolate the opening from any liquid that may be at the bottom of the reservoir. Moreover, in case the impregnated element is an elastically deformable element, it is axially guided in the compartment when the applicator is caused to bear on its upper surface. Causing the applicator to bear on such an elastically deformable element with open cells or half-open cells, followed by the extraction of the applicator, firstly produces an at least partial compression of the open cells or half-open cells, then the decompression of the cells, which causes the liquid to be drawn up towards the restoring surface of the impregnated element.
The second end of the element containing the liquid composition may be substantially in contact with the bottom. Advantageously, the second compartment defines, all around the element in the vicinity of the bottom, an annular space defining a volume capable of containing a reserve of the liquid composition for feeding the element, the element being capable of drawing up the liquid composition from the reserve.
Alternatively, the second end is situated in a fixed intermediate position between the bottom and the second opening so as to define, between the bottom and the second end, a volume capable of containing a reserve of the liquid composition for feeding the element, the element being capable of drawing up the liquid composition from the reserve. Bringing the liquid contained in the reserve into contact with the element, in particular, is effected by completely or partially upending the application unit. This is produced quite naturally, in particular while such a packaging unit is being carried in the user""s handbag. Alternatively, a wick-type element may be provided which dips into the reserve of the liquid which rises up by virtue of the capillarity drawing phenomenon.
The applicator may be a styptic pencil, or a stick of lipstick, of a make-up foundation, of polyvinyl alcohol (PVA), of guar gum, or ok a skin treatment product. The liquid composition may contain water or any other solvent, and/or preservatives, and/or film-forming elements and/or emollients, and/or active compounds.
The application unit in accordance with the invention may comprise means for allowing the second compartment to be detachably mounted relative to the first. This allows the applicator and the container containing the liquid composition to be sold separately, if desired. It also makes it possible to allow the same stick to be used in combination with several liquid compositions according to the user""s requirements.
According to a particular embodiment, the two compartments are disposed head-to-tail and aligned along the same axis and disposed so that the first and second openings are situated in directions opposite to one another. This arrangement reduces the size and allows a unit to be made of a shape similar to that of conventional sticks.
The second compartment may have an auxiliary opening for mounting the impregnated element inside the second element, or for replacing it after the liquid composition contained therein has been used up. This auxiliary opening may also be used for adding liquid to the second compartment, detachable means being provided for obturating the auxiliary opening in a leakproof manner.
The applicator is preferably carried by a gripping element ensuring the leakproof closure of the first opening. For this purpose, the gripping element has a frustoconical portion capable of cooperating with a complementary profile of the first opening. This seal may be desirable for certain formulas. On the other hand, for other formulas it may be arranged that the applicator is not contained in a leakproof manner inside the first compartment, so as to permit the evaporation of certain kinds of substances and, if applicable, to permit the drying out of the formula. A cover cap may optionally be disposed on the unit in a detachable manner.
The gripping element advantageously has means for limiting the insertion of the applicator into the second compartment. By way of example, a shoulder may be formed at the level of the gripping element. This makes it possible to restrict the force that can be exerted on the foam block. An excessive force could be detrimental both to the applicator and the element impregnated with the liquid composition. However, the travel of the applicator, the position of the foam block and its height must be chosen so as to be sufficient for the applicator to be brought to bear on the foam block irrespective of the extent to which the product for the applicator has been consumed.
The applicator is preferably disposed in a cup carried by the gripping element, the applicator being formed by molding or extrusion.
The second opening is obturated in a leakproof manner by means of a lip or a frustoconical element which is carried by a detachable cap, and which is capable of cooperating with a complementary profile of the second opening. The detachable cap may be designed so as to obturate only the second opening. Advantageously, it forms a single part with the cover cap disposed on the applicator opposite the first compartment.
A sealing element in the form of an annular piece made of an elastomeric material may be disposed inside the second opening, so as to perfect the seal of the closure of the second compartment. Advantageously, the sealing element is disposed so as to limit the axial movement of the impregnated element, to prevent the emergence of the element through the second opening.
The applicator may have any cross-section. For example, it may have a cross-section which is circular, triangular, square, oval, elliptical, etc. The internal cross-section of the second compartment is matched to the shape of the applicator.